Ald pulse sequence engineering for improved conformality for low temp precursors

Abstract

The present disclosure relates to methods, systems, and apparatuses for depositing films. In particular, a film is deposited using an atomic layer deposition process where some steps of the ALD process are performed at a temperature above a pyrolysis temperature of a film precursor.

1 . A method of depositing a film, the method comprising:
 providing a substrate in a process chamber; and   performing one or more cycles of an atomic layer deposition (ALD) process, wherein each of the one or more cycles of the ALD process comprises:   (a) exposing the substrate to a precursor, wherein the substrate is at a first temperature during at least a portion of (a), wherein the first temperature is below a pyrolysis temperature of the precursor; and   (b) exposing the substrate to one or more reactants, wherein during at least a portion of (b) the substrate is at a second temperature above the pyrolysis temperature.   
     
     
         2 . The method of  claim 1 , wherein during (b) the process chamber is at a first pressure, and the method further comprises, before (a):
 (c) exposing the substrate to a purge gas, wherein during (c) the process chamber is at a second pressure less than the first pressure.   
     
     
         3 . The method of  claim 2 , wherein during (c) the temperature of the substrate decreases from the second temperature to the first temperature. 
     
     
         4 . The method of  claim 2 , wherein a duration of (c) is at least about 5 seconds. 
     
     
         5 . The method of  claim 2 , wherein the first pressure is at least about 5 Torr, and the second pressure is less than about 1 Torr. 
     
     
         6 . The method of  claim 5 , wherein the second pressure is less than about 0.1 Torr. 
     
     
         7 . The method of  claim 2 , wherein the process chamber is at a third pressure during (a), and the third pressure is less than the first pressure. 
     
     
         8 . The method of  claim 2 , wherein the purge gas comprises an inert gas. 
     
     
         9 . The method of  claim 2 , wherein the purge gas comprises H 2 . 
     
     
         10 . The method of  claim 1 , wherein the second temperature is at least about 600° C. 
     
     
         11 . The method of  claim 1 , wherein the pyrolysis temperature is between about 500° C. and about 600° C. 
     
     
         12 . The method of  claim 1 , wherein (b) is performed in the presence of a plasma. 
     
     
         13 . The method of  claim 12 , wherein a power of the plasma is at least about 5000 W. 
     
     
         14 . The method of  claim 1 , wherein the precursor is a silicon-containing precursor. 
     
     
         15 . The method of  claim 1 , wherein the precursor is a carbon-containing precursor. 
     
     
         16 . The method of  claim 1 , wherein the one or more reactants comprise a nitrogen-containing reactant. 
     
     
         17 . The method of  claim 1 , wherein the one or more reactants comprise an oxygen-containing reactant. 
     
     
         18 . The method of  claim 1 , wherein the ALD process forms a conformal film. 
     
     
         19 . The method of  claim 18 , wherein the conformal film is a silicon nitride film. 
     
     
         20 . The method of  claim 1 , wherein the substrate comprises features having an aspect ratio of at least about 30:1. 
     
     
         21 . The method of  claim 1 , wherein process chamber comprises a pedestal, and the pedestal temperature is about the second temperature during (a).